Great work Martin, thats amazing endurance, any longer and you'll have to work out how to cope with varying temperature changes expanding or contracting the helium. The airships too small to have an internal ballonet.

Hi Adam I have tested a ballonet system in a similar airship. It is more about maintaining the correct envelope pressure while on the ground, between sun and cloud cover, is less of a problem once in the air.

I have tested it with Flight controller/OSD/waypoints etc.

The overall aim of this development is not just to build and fly a one off RC airship, many people have done that for years. It is to build and operate an RC airship more like a Drone/Multicopter but with long endurance ( Solar power will be tested at some point ) at an affordable price i.e.keep it as small as possible with Helium recovery /storage and transport. Around 1 cubic meter vol is the sweet spot for the RC Airship to carry a camera system the same as drones between 500 - £1000, but 4 times the endurance.